1. Field
Example embodiments of the present disclosure relate to an Unequal Error Protection (UEP) method and apparatus for transmitting various types of uncompressed video signals in a broadband high frequency wireless system, and more particularly, to a UEP method and apparatus for transmitting and receiving various types of uncompressed video signals, which are immune to radio channel errors, according to a priority of the video signals while maintaining a high transmission/reception speed.
2. Description of the Related Art
Unlike general data information in which priorities of all data information bits are the same, video information may have different priorities of video information bits. For example, upper bits of pixel bytes displaying images may be more important than lower bits thereof, and luminance information bits of an image may be more important than chrominance information bits of the image. Also, in an RGB chromatic system being comprised of Red elements, Green elements, and Blue elements, the Green elements are more important.
In general, the video information may be required to be transmitted at a high speed because an amount of the video information is significantly greater than that of the general data information and the video information requires real-time performance in information transmission. In addition, channel errors may occur in a radio channel due to various factors, resulting in transformation of transmitted information. To minimize the transformation of the information due to the radio channel errors, supplementary information (hereinafter, referred to as channel error correction code) may be added to information intended to be transmitted in a transmission terminal, and transformed information may be restored in a reception terminal using the added channel error correction code. However, the channel error correction code information may reduce a transmission speed of a channel.
Concerning the priority of the video information and characteristics of the radio channel, a recent ‘high transmission speed radio system through an ultra-wideband high frequency band’ may categorize upper bits and lower bits of pixel information bytes being comprised of image information, and use more channel error correction code information in the upper bits and use less channel error correction code information in the lower bits, thereby preventing transformation of important information, and improving image quality. As described above, adapting unequal error correction schemes according to a priority of signals may be referred to as an Unequal Error Protection (UEP) scheme.
FIG. 1 illustrates a UEP scheme of general uncompressed videos according to a conventional invention. In the UEP scheme illustrated in FIG. 1, RGB (Red, Green, and Blue) pixel data each having an 8-bit field may be separated into 4 bits/4 bits, 3 bits/5 bits, and 2 bits/2 bits/4 bits to assign a high priority to upper bits, and thereby the channel error correction code may be unequally assigned.
However, the above-mentioned UEP scheme may display the priority using common bit position of three element information (RGB information or YCbCr information) being comprised of a pixel. Also, according to the above-mentioned UEP scheme, a case where each of the three element information is displayed as identical 8-bits may be considered. That is, since the priority may be classified only using common bit positions of the pixel information, a priority difference between luminance information (corresponding to Y in a YCbCr system) and chrominance information (corresponding to CbCr in the YCbCr system), and a priority difference between Green information and Red/Blue information in the RGB chromatic system may not be used. Also, the above-mentioned UEP scheme may not support pixel information displayed as various depths such as 8-bits/16-bits/32-bits and the like, because the color depth is required to be separated into 8-bits/8-bits when being displayed as 16-bit color space information, however, when the color depth is separated into a 4-bit unit as illustrated in FIG. 2, 4th bit to 7th bit positions may be assigned with more stronger channel error correction codes than in 8th bit to 12th bit positions.
FIG. 2 illustrates an example of errors occurring according to a color depth and bit separation position in a UEP scheme of general videos.